Dynamic characteristics of nutrients in striped cutting Moso bamboo forests

  Objective  This paper aims to study the dynamics of nitrogen (N), phosphorus (P), and potassium (K) nutrients in Moso bamboo forest after strip cutting, so as to provide a scientific basis for nutrient management strategies in the amboo forest after logging.

  Method  We selected the 8 m bandwidth strip cutting sample plots (SC) and its reserved sample plots (RB) as the research object, and the traditional management forest (CK) as control. The biomass of Moso bamboo, understory vegetation, litter yield, and corresponding nutrient contents of each component was investigated for five years after cutting. Therefore, nutrient flux was quantified, and the nutrient cycling coefficient of the Moso bamboo forest was calculated. The characteristics of nutrient flow and cycling were compared among different treatment sample plots.

  Result  (1) In the first year after cutting, there was no significant difference in the retention of N, P, and K among different treatment sample plots. The return of nitrogen in SC was decreased. (2) Three years after cutting, the retention of N, P, and K in the RB was less than that in SC and CK. The return of nitrogen in SC and RB was significantly lower than that in CK. (3) Five years after cutting, the retention of nitrogen in RB was less than that in SC and CK. There was no significant difference in the amount of N, P and K returned and nutrient storage between SC and CK. (4) Strip cutting significantly increased the utilization coefficients of N, P (P < 0.05). With the restoration of sample plots, the utilization coefficient of each nutrient gradually decreased, and there was no difference with CK. Cutting had no significant effect on the cycling coefficients of N, P and K.

  Conclusion  Five years after cutting, nitrogen, phosphorus, and potassium nutrient storage reaches the level of pre-cutting and CK. From the perspective of nutrient cycle, it is proved that SC could recover to the level of CK after 5 years. However, the nutrient use coefficient and recycling coefficient of RB gradually decrease from the second on-year after cutting, and density control management is needed to improve the nutrient use efficiency.